package com.kuang.pc;

/**
 * @program: juc
 * @description:线程之间的通信问题，生产者和消费者问题!  等待   通知
 * @author: 陈恩涛
 * @create: 2021-01-29 10:46
 **/

/*
* 线程交替执行  A  B操作同一个变量 num = 0
* A num+1
* B num-1
* */
public class A {
    public static void main(String[] args) {
        Data data = new Data();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.increase();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrease();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.increase();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"C").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrease();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }
}

// 资源类   数字
// 判断等待  业务  通知
class Data{
    private int number = 0;

    //+1
    public synchronized void increase() throws InterruptedException {
        while (number != 0) {
            //等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程，我完成了+1
        this.notifyAll();
    }


    //-1
    public synchronized void decrease() throws InterruptedException {
        while (number == 0) {
            //等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程，我完成了-1
        this.notifyAll();
    }
}
